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In this study, functionalized graphene is used as a carbon-based material to support platinum-ruthenium bimetallic nanoparticles and to improve methanol oxidation reaction activity due to the enhanced physical and electrical properties of graphene. First, surface oxidation is used for creating oxygen functional groups, and then nitrogen doping by thermal treatment with ammonia as the nitrogen precursor. Platinum-ruthenium alloy nanoparticles are dispersed by the impregnation reduction method on the support materials. The final nanocomposite samples contain 8% of oxygen and 3% of nitrogen. Compared to PtRu/GNS and PtRu/CB, the PtRu/NO-GNS catalyst indicates 1.25 and 1.3 times higher surface area, and 2.3 and 4 times higher electrochemical surface area, respectively. The highest methanol oxidation current density of 305 mA/mg and 262 mA/mg is obtained for platinum-ruthenium supported on nitrogen-doped graphene and nitrogen-doped oxidized graphene, which is 2.9 and 2.5 times higher than that for PtRu/GNS, respectively. It is revealed that the nitrogen-doped samples have shown greater activity and long-term stability than other electrocatalysts, including the widely used carbon black supported catalyst.Hence, this work reports the performance of an efficient alternative electrocatalyst with practical application in direct methanol fuel cells.

Summary In this research, a novel integrated system for renewable hydrogen production, power, and hot water from solar thermal energy has been developed and precisely evaluated in terms of thermodynamics. The developed structure is comprised of a four‐step Cu‐Cl thermochemical cycle, and an organic Rankine cycle to generate electricity. The required heat is supplied by a concentrated solar power plant and thermal energy storage based on latent heat. Also, a high‐temperature heat pump is employed to improve the thermal grade of working fluid and provide each unit with sufficient heat. System dynamics simulation has been performed using weather and irradiation input data of Tehran, Iran. The integrated structure has the capability to produce 21.75 kg/h of hydrogen, 563.6 kW of electricity, and 393.3 m3/h of hot water at 70°C. The energy efficiency of the system reaches more than 80% based on higher heating value and the solar‐to‐fuel efficiency has a value of 25.8%. Moreover, an exergy analysis has been executed to determine the fundamental operating parameters of each component and the whole structure. The total exergy efficiency of the integrated structure is 34.23%, and the prime cost of the product is found to be 5.795 USD/kg H2.